Dyes, synthetic

More recently, these dyes were the subject of an important chapter by Ficken in Venkataraman s volume published in 1971, The Chemistry of Synthetic Dyes, which covers supplementary chemical knowledge (2). 

As early as 2500 bce m India indigo was used to dye cloth a deep blue The early Phoenicians discovered that a purple dye of great value Tyrian purple could be extracted from a Mediterranean sea snail The beauty of the color and its scarcity made purple the color of royalty The availability of dyestuffs underwent an abrupt change m 1856 when William Henry Perkin an 18 year old student accidentally discovered a simple way to prepare a deep purple dye which he called mauveme from extracts of coal tar This led to a search for other synthetic dyes and forged a permanent link between industry and chemical research... 

Natural sensitizers Natural tannins Natural vs synthetic dyes Nature ofinvention Nausea N.S. Nautilus Naval brass... 

H. A. hubs, ed.. The Chemistry of Synthetic Dyes and Pigments, American Chemical Society Monograph Series, Reinhold Publishing Corp., New York, 1955. 

E. Gurr, Synthetic Dyes in Biology, Medicine and Chemistry, Academic Press, London, 1971. 

High Pressure in the Chemical Industry. The use of high pressure in industry may be traced to early efforts to Hquefy the so-called permanent gases using a combination of pressure and low temperature. At about the same time the chemical industry was becoming involved in high pressure processes. The discovery of mauveine in 1856 led to the development of the synthetic dye industry which was well estabUshed, particularly in Germany, by the end of the century. Some of the intermediate compounds required for the production of dyes were produced, in autoclaves, at pressures of 5-8 MPa (725-1160 psi). 

K. Venkataraman, The Chemisty of Synthetic Dyes, Vol. V, Academic Press, Inc., New York, 1971. 

Oxidation. Aromatic amines can undergo a variety of oxidation reactions, depending on the oxidizing agent and the reaction conditions. For example, oxidation of aniline can lead to formation of phenyUiydroxylamine, nitrosobenzene, nitrobenzene, azobenzene, azoxybenzene or -benzoquinone. Oxidation was of great importance in the early stages of the development of aniline and the manufacture of synthetic dyes, such as aniline black and Perkin s mauve. 

Dyes, Dye Intermediates, and Naphthalene. Several thousand different synthetic dyes are known, having a total worldwide consumption of 298 million kg/yr (see Dyes AND dye intermediates). Many dyes contain some form of sulfonate as —SO H, —SO Na, or —SO2NH2. Acid dyes, solvent dyes, basic dyes, disperse dyes, fiber-reactive dyes, and vat dyes can have one or more sulfonic acid groups incorporated into their molecular stmcture. The raw materials used for the manufacture of dyes are mainly aromatic hydrocarbons (67—74) and include ben2ene, toluene, naphthalene, anthracene, pyrene, phenol (qv), pyridine, and carba2ole. Anthraquinone sulfonic acid is an important dye intermediate and is prepared by sulfonation of anthraquinone using sulfur trioxide and sulfuric acid. 

Sulfonic Acid-Based Dyestuffs. Sulfonic acid-derived dyes are utilized industrially in the areas of textiles (qv), paper, cosmetics (qv), foods, detergents, soaps, leather, and inks, both as reactive and disperse dyes. Of the principal classes of dyes, sulfonic acid derivatives find utiUty in the areas of acid, azoic, direct, disperse, and fiber-reactive dyes. In 1994, 120,930 t of synthetic dyes were manufactured in the United States, of which 5,600 t were acidic (74). The three largest manufacturers of sulfonic acid-based dyes for use in the United States are BASF, Bayer, and Ciba-Geigy. 

Inthion and Dykoflte synthetic dyes Bunte Inthion Brilliant Blue Condense S Blue 2 Cl 18790 [12224-49-6] ... 

Triphenylmethane dyes comprise one of the oldest classes of synthetic dyes. They are of bdUiant hue, exhibit high tinctorial strength, are relatively inexpensive, and may be appHed to a wide range of substrates. However, they are seriously deficient in fastness properties, especially fastness to light and... 

Azine, oxazine, and thiazine dyes were among the earliest of synthetic dyes. The names are derived from the 6-member heterocycHc ring system present in... 

Azines were the first of the synthetic dyes. Perkins oxidized a cmde mixture of aniline containing toluidines and obtained mauveine (7). 

K. Venkataraman, Tie Chemistry of Synthetic Dyes, Vols. 1 and 2, Academic Press, New York, 1952. 

F. Kaspr2ak and B. Glebko, Chemik 19, 267—273 (1966). Dyes for Foods, Pharmaceuticals, and Cosmetics. Natural and synthetic dyes produced in Poland and other countries are described and compared. 

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